On my Denon, it does not matter where you have the volume control, it bypasses that setting and automatically plays the pink noise at the appropriate levels for calibration.
Depends on the sub, if you have one of Axiom EP subs, I would start at a lower setting on the gain control. Other subs, start about midway. After you've done it a few times you will get the hang of it....I always try to shoot for around 0dB on my receiver, if you end up being to low, say -10dB, then lower the volume on the sub.
